Each set of resources in the game can be collected three times each resulting in three rewards. The first reward is always a card that is unique to the treasures, the second card is an ISO-8 rare, and the third card is the same card as the first so the player can fuse it into a final form.
Storms Cape is the first resource and results in the card (Queen of Lightning) Storm.
(Queen of Lightning) Storm has roughly 3000 atk/def when maxed. In final form she is approaching 4000 atk/def for only 10pwr.
Suitcase is the second resource and results in the card (Legal-Eagle) She-Hulk.
(Legal-Eagle) She-Hulk has roughly 3300 atk/def when maxed. In final form she is just under 4700 atk/def for only 12pwr.
Sword of Proficiency is the third resource and results in the card Taskmaster.
Taskmaster has roughly 3500 atk/def when maxed. In final form he is just under 5000 atk/def for only 14 pwr.
Assassin's Choker is the fourth resource and results in the card X-23.
X-23 has roughly 3800 atk/def when maxed. In final form she is just over 5000 atk/def for only 16 pwr.
Completion of all four sets will result in 8 Rare cards and 4 ISO-8. Another thing to note is that since these cards are very abundant, they are worth far less than normal rares. But X-23 and Taskmaster are worth considering maxing and using in your deck.